Double-Roast Sweet Potatoes For Crispy, Caramelized Spuds
Many sweet potato recipes will play into the tuber's eponymous flavor by heaping on yet more sweetener — think marshmallow-topped sweet potato casserole or sweet potato pie. Sweet potatoes, however, are plenty sweet all on their own when roasted, but they also tend to be a bit on the squishy side. The reason for both of these things is that up to ¾ of the starch in these potatoes converts to sugar as they cook, so while they make super-flavorful mashed potatoes, they tend to lack the structural integrity you might want in a roast potato. There is a way to help combat this, though, and that's to roast them twice.
The first time around, keep the sweet potatoes intact. Bake them at 350 F until you can stick a fork in them, then crank up the heat to 475 F (raising the temperature will also help caramelize your spuds). While the oven is re-preheating, take the potatoes out and let them cool. Once you can pick them up without burning your hands, do so. If you prefer symmetrical spuds, cut them into cubes, but if you don't mind going rustic, rip them apart into maybe five or six pieces per potato. If you opt to go the latter route, the rough edges may help to provide some extra crispiness when cooked. Sprinkle them with the cooking oil of your choice, then roast them for 20 to 30 minutes more until the flesh begins to brown and the skin starts to char.
Parboil potatoes before roasting to improve the flavor
Another way to crisp up your sweet potatoes also involves cooking them twice, but instead of using the oven both times, the first time you'll be boiling them. While it may seem to fly in the face of reason to boil the potatoes before baking them since you'd think it would make them even softer, it actually serves the purpose in several ways. For one thing, boiling the sweet potatoes prior to roasting them means that they take less time in the oven which is where their starch turns to sugar. For another, you can add about ½ teaspoon baking soda to the water before boiling potatoes chopped into chunks. The alkaline water will erode the potato surface just a bit, allowing it to cook up crisper than smooth flesh.
Cook the potatoes in boiling water for about 10 minutes, then drain them and toss them with oil and potato or cornstarch as well as some salt and any other seasonings you'd like to use. The purpose of the added starch is to help replace any of the potatoes' own starch that they'll lose as they bake and create a crispy coating. Speaking of baking, once the potatoes are coated, cook them at 450 F for about 35 minutes, then allow them to cool in the oven for another 10 minutes or so. At this point, take them out and eat them while they're still hot and crunchy.